DONNA CASEY, Sun Media

The gifted chemistry professor who threw Christmas parties at the bowling alley. The dad caught in the happy craziness of raising three young kids.

Today, the people who knew and loved Keith Fagnou are heartbroken and wondering how a healthy young man could go from the picture of health to death in five days.

It’s a question with few answers.

Fagnou, 38, died Wednesday in the intensive care unit at the Ottawa Hospital, three days after he was admitted with suspected swine flu. The award-winning University of Ottawa chemistry professor had no underlying medical conditions. His death is the city’s fourth H1N1-related death since September.

“I still can’t really believe it,” said cousin Brent Fagnou, who grew up with Keith in Saskatoon.

“The biggest thing is his kids — it’s just too young to die,” said Brent of his cousin’s children, Zachary, 8, Clare, 4, and 18-month-old Samuel.

Fagnou’s wife, Dr. Danielle Gervais-Fagnou, is a family doctor with the University of Ottawa’s health services clinic.

Fagnou joined the university’s faculty of science in 2002 and a year later won the prestigious Polanyi Prize for his research on more efficient ways of preparing complex molecules. His work was part of the “green chemistry” movement with broad implications for sustainable development practices.

In 2007, Fagnou was promoted to associate professor and was awarded a research chair in novel catalytic transformation. Members of his research team — dubbed the “Fagnou Factory” — were reeling yesterday from the news of their mentor’s death.